This is an individual National Research Service Award for pre-doctoral research training, which provides support for promising doctoral candidates who will be performing dissertation research and training in a scientific health-related field. From a public health perspective, it is imperative to learn more about the neural systems underlying obsessiveness and compulsiveness in autism spectrum disorders (ASD), given the high prevalence of these symptoms in ASD patients. Recent studies have identified functional abnormalities of the default network (i.e., a set of brain regions activated during passive task states and whose activity and function may play an important role in the development of several neuropsychiatric disorders). In addition, recent studies of ASD have shown that the disorder may be largely characterized by deficits in cognitive processes under the control of default mode structures (i.e., known to modulate social, emotional, self-relevant tasks) that might be due to dysfunction of the default network. The study proposed here aims to better understand this brain-behavior relationship. This knowledge may suggest new therapeutic routes and diagnostic techniques to help treat obsessive and compulsive symptoms in ASD.